Process of extracting potassium chlorid from fuci and algæ.



UNITED STATES Patented December 15, 1903.

PATENT OFFICE.

DAVID M. BALCH, OF CORONADO, CALIFORNIA, ASSIGNOR OF ONE-HALF TO ANSON P. STEPHENS, OF CORONADO, CALIFORNIA.

PROCESS OF EXTRACTING POTASSIUM CHLORED FROM FUCl AND ALG/E.

SPECIFICATION forming part of Letters Patent No. 747,291, dated December 15, 19031. Application filed March 24;, 1902. Serial No. 99,801. (No specimens.)

To a whom it may concern:

Be it known that I, DAVID M. BALCH, a citizen of the United States of America, residing at Coronado, in the county of San Diego and State of California, have invented a new and useful Process of Extracting Potassium Chlorid from Fuci and Algte, of which the following is a specification.

My improved process relates to the extracro tion of potassium compounds from fuci and algae, and refers more particularly to those classes of seaweeds generally to be found on the American coast, which seaweeds are very rich in alkaline salts and contain scarcely a r 5 trace of iodin, in contradistinction to those families of seaweeds known as Lamzmam'a digitata and Stenophylla found in European waters, which are exceedingly rich in iodin and relatively poor in alkaline salts.

The object attained by my process is the economical manufacture of potassium compounds in merchantable quantities, to accomplish which I proceed as follows:

First. The weed is gathered and thoroughly sun-dried, after which it is coarsely cut or broken up. I then dust or coat the material with an alkaline substance, which may consist of an intimate mixture of the carbonate and hydrate of an alkaline earth-such as 0 calcium, barium, strontium, or air-slaked lime, preferably the latter. A mixture of forty grams of lime to each kilogram of the dried seaweed will yield the best results; but the proportions may vary.

Second. The broken seaweed thus treated is now placed in air-tight retorts, chambers, or in any suitable receptacle and lightly compressed, and heat is applied thereto in any desirable manner within or without the re- 40 ceptacles, the degree of heat being sufficiently high to completely decompose the organic portion of the seaweed, but not high enough to break up the sulfates present, which would result in vitiating the products ulti- 5 mately to be obtained by the sulfids or sulfur lower oxids which would thus be liberated. The effect of the heat upon the commingled seaweed and alkaline substance is to char the material.

Third. The retorts or chambers are connected with suitable condensing appliances and to receivers, and all condensible volatile products arising from this modified form of dry distillation, together with the unco'ndensible gases generated, are collected apart. The heating of the retorts or chambers is maintained until no further volatile products are evolved.

Fourth. The non-volatile residuum of the above operation remaining in the retorts comprises a char, which consists of a light porous carbon intimately com mingled with the mineral salts of the fuci and with the added alkaline substance, such as lime. This residuum I may grind or pulverize to a coarse powder, or I may utilize it just as it comes from the retorts. In either case this residuum is lixiviated with the least possible quantity of water, either hot or cold, in suitable vessels, such as percolators or tanks. The resulting saline solution is perfectly colorless and may now be evaporated to crystallization or to dryness by either sun or artificial heat, leaving a purely White product, which is merchantable potassium chlorid. Thus it 75, will be seen that by the simple and direct methodhereinabove detailed I obtain without further manipulation the product sought, and this product so obtained needs no further purification, the char yielding commer- 8o cially-pure potassium compounds upon lixiviation.

Fifth. Instead of evaporating the saline liquor received from the percolators, such solution may be treated by any of the wellknown methods for the purpose of obtaining other potassium compoundssuch, for instance, as saltpeter.

The condensible volatile products which are released during the charring of the material differ essentially from the vapors yielded by wood under similar treatment, for the reason that the seaweed contains very little cellulose. When these products are more thoroughly examined, they will, no doubt, 5 yield important merchantable material.

The uncondensible gases which are evolved during the charring process and which are collected apart from the volatile condensible products when purified may be used for heat- :00 ing or illuminating purposes.

The exhausted material remaining in the tanks or percolators after the leaching process may be utilized as fuel, as a basis for fertilizers, or in any other suitable manner.

From the foregoing it will be seen that my invention to a great extent depends for the accomplishment of the result upon the presence of the alkaline substances, such as airslaked lime, with which the dried broken seaweed is coated before being treated in the retorts. The action of these alkaline substances seems to favor the complete separation of the soluble from the insoluble mineral salts of the particular fuci under treatment and is of decided advantage in breaking'up and converting into ammonia certain difficultly-decomposable nitrogenous constituents of the seaweed. The efliciency of these alkaline substances, and particularly of air-slaked lime, has been established to my satisfaction by numerous experimental and practical operations, and by the use of these substances I am enabled to extract from the seaweed directly the products sought economically and in merchantable quantities and condition. The decomposition elements which would otherwise contaminate the product obtained are either prevented or removed by the presence of the finely-divided lime or other alkaline substance in the retorts or other heatingreceptacle.

The potassium salts contained in the solution obtained from the char can be technically easily separated from the sodium salts likewise contained therein.

It is obvious that changes might be made in the foregoing process and in the ingredients used, the manner of compounding, and the proportions. Hence I do not wish to limit myself to the exact method herein set forth; but

What I claim as new, and desire to secure by Letters Patent, is

1. The herein-described process of treating seaweed for the extraction of potassium salts therefrom consisting in drying the seaweed, coarsely cutting or breaking it up, dusting the weed with lime or other alkaline subtance, placing the seaweed in air-tight receptacles under pressure, heating the receptacles to decompose the organic portion of the weed and charring the material, grinding or pulverizing the charred residuum, lixiviating the residuum, and evaporating the clear solution obtained thereby directly yielding colorless merchantable potassium chlorid.

2. The herein-described process of treating seaweed for the extraction of potassium salts therefrom consisting in drying the seaweed, coarsely cutting or breaking it up, dusting the weed with lime or other alkaline substance, placing the seaweed in air-tight receptacles,heating the receptacles to decompose the organic portion of the weed and charring the material, grinding or pulverizing the charred residuum, lixiviating the residuum, and evaporating the clear solution obtained thereby directly yielding colorless merchant able potassium chlorid.

. In witness that I claim the foregoing I have hereunto subscribed my name this 15th day of March, 1902.

DAVID M. BALOH.

Witnesses:

HENRY T. HAZARD, G. E. HARPHAM. 

